Guidance Manual: Water Quality in Drinking Water Distribution Systems (original) (raw)

Drinking water treatment in The Netherlands: outstanding and still ambitious

Water treatment in The Netherlands has developed to an outstanding level. Nevertheless, new challenges, such as protozoa (e.g. Cryptosporidium), Legionella, endocrine disrupting compounds and pharmaceuticals, have to be faced. These challenges can have a negative effect on customer confidence and the overall reputation of water supply. The Dutch water supply companies therefore have set a new ambition for water quality. To realize this ambition an integral approach to water treatment involving new technologies as membrane filtration and UV is necessary. The paper will present the possibilities of the current level of technology, how it relates to the vision and ambition of the Dutch drinking water sector and the role of research -especially in UV technology and membrane filtration -in realizing long-term goals.

2006 PAPER-Quality Control of Drinking Water and Public Health

The 60/2000/EU (WFD) and 98/83/EEU directives imposed rules and instructions for continuous monitoring and control the quality of drinking water. In the present study three representative areas, lowland (LL), mountainous (M) and coastal (C), have been selected for the collection of water samples, in the Prefectures of Larissa, Karditsa and Magnissia, central Greece. Physical: (electric conductivity (EC, μS/cm), pH, total hardness (TH, mg/L CaCO 3 )), chemical (mg/L): (nitrate (NO 3 -), nitrite (NO 2 -), potassium (K + ), sodium (Na + ), ammonium (NH 4 + ), calcium (Ca +2 ) and magnesium (Mg +2 )) and microbiological: (total coliforms, E. Coli, Enterococci, Pseudomonas Aeroginosa and Salmonella) parameters have been determined and analyzed for the period 2004-05. The mean values of the studied physical and chemical parameters were found to be within the limits mentioned in the 98/83/EEC Directive. From the microbiological study can be concluded that the water was inapropriate for human consumption in many cases because of the presence of microbes. From the analysis of results (Student's t-test; P<0.05 and Mann-Whitney test; P<0.05), it reveals that there are significant differences on the water quality among the studied areas.

Quality Control of Drinking Water and Public Health

Safe Drinking Water: Concepts, Benefits, Principles and Standards

Water Challenges of an Urbanizing World, 2018

Water is connected to every forms of life on earth. As a criteria, an adequate, reliable, clean, accessible, acceptable and safe drinking water supply has to be available for various users. The United Nation (UN) and other countries declared access to safe drinking water as a fundamental human right, and an essential step towards improving living standards. Access to water was one of the main goal of Millinium Development Goals (UN-MDGs) and it is also one of the main goal of the Sustainable Development Goals (SDGs). The UN-SDG goal 6 states that "Water sustains life, but safe clean drinking water defines civilization". Despite these facts, there are inequalities in access to safe drinking water in the world. In some countries, sufficient freshwater is not available (physical scarcity); while in other countries, abundant freshwater is available, but it is expensive to use (economic scarcity). The other challenge is the increasing population of the world at an alarming rate, while the available freshwater resources almost remains constant. This chapter presents aspects of safe drinking water -background information, definition of water safety and access, benefits, principles and regulations, factors challenging the sustainable water supply and water quality standards and parameters.

Drinking Water Quality in Water-Supply Networks

Environmental Engineering and Management Journal, 2011

The paper describes some studies on the influence of water flow rates through water-supply networks on drinking water quality. Water residence time in pipelines for more than seven days in buried pipes and two days in above-ground pipes promotes the development of biochemical systems when the flow rates are low and very low having detrimental consequences on drinking water quality. These shortcomings are due to the residual chlorine decrease below the allowed technical limits (0.5 m/s) as a consequence of the fact that in distribution pipes, fittings and drain junctions the water flows at low rates reaching far to stagnate over the admitted residences. The case study was conducted on the water-supply network in the city of Timişoara using the EPANET program. The hydraulic parameters (flow, diameter, flow rate, loss of head) of EPANET are correlated with the water stagnation periods (residents) on pipe sections with residual chlorine allowed at every point of consumption. After analyzing the distribution of water flow rates in the network, it was concluded that in almost all situations these were between 0.3-0.9 m/s. For a safe disinfection, the residual chlorine in drinking water must be at least 0.3 mg/L.

Water quality modelling for drinking water distribution systems

Proceedings MODSIM 2003

A dynamic water quality model for drinking water distribution systems has been developed in this study, to include processes that occur in the bulk water, as well as those occurring in the biofilm of a distribution system. The model has been validated against water quality data obtained from extensive experimental studies conducted with biofilm reactors. Protein and carbohydrate densities in the biofilm represent biofilm biomass. This model is able to predict the disinfectant decay due to organic matter in the bulk water, as well as that due to biofilm. It simultaneously predicts the growth of biofilm in terms of carbohydrate and protein densities. While this model is complex enough to describe the water quality changes in a distribution system, it is also simple enough to be incorporated into a hydraulic model in order to describe the interaction between disinfectant and microbiological quality throughout a drinking water distribution system.

Water intended for human consumption — Part I: Compliance with European water quality standards

Desalination, 2005

Among the European Union Directives enacted on water management and environmental protection, Directive 98/83/EC defines the mandatory quality standards for water intended for human consumption in order to protect human health. The implementation of this Directive has often encountered delays due to the following: the exact mechanisms for monitoring and enforcement have not yet been fully identified, several EU countries had set more stringent drinking water standards while others needed to update their national regulation, financial resources to comply with the directive were not always available, and the recent enlargement of the EU has raised further issues. In this study an evaluation of the regulations on drinking water in European and Mediterranean countries was carried out. The attention focused on Directive 98/83/EC and to its implementation in the Member States, also considering the recent (2004) EU enlargement, which brought ten new countries into the European Union. Finally, a comparison among the new standards on disinfection by-products (DBPs) adopted by the different countries is presented along with the USEPA approach to DBPs control.

Water Quality Correction Within Water Distribution System

Ecological Chemistry and Engineering S, 2015

Water suppliers can be treated as production companies whose main product is water delivered to their customers. The article presents problems connected with management of such companies in the conditions of secondary contamination in water distribution systems. This phenomenon exists in water networks all over the world. Its’ presence is particularly visible in countries of former communistic block. In the article particular attention was devoted to the issue of water quality correction in the analysed systems. In the case of water distribution systems, former quality correction methods consisted in special treatment of water pumped into the system, flushing and cleaning of water pipes. In both these cases identification of water quality deficiencies resulted in significant water loss. The situation reflects management processes applied in the manufacturing industry of the 1940s. The authors of this paper put forward the concept of three water quality correction methods which would...

Assessment of Drinking Water Quality from Treatment Plants and Consumers

SIMI 2018, 2018

The present study investigated the quality of potable water that was taken from the treatment plants in three counties from Romania (Ialomița, Gorj and Tulcea) for a two-year period (2016 and 2017). A series of organic and inorganic indicators have been analyzed in the drinking water from the respective locations. Out of the 37 samples collected in Ialomița county in 2016, the following indicators have exceeded the maximum admissible concentrations (MAC): sodium in 8% of the total samples, nitrogen in 38%, copper in 27%, manganese in 5%, iron, nickel and chromium in 3% of the samples. In Gorj County, samples from 25 locations were analyzed during 2017. Exceedings of MAC were recorded for hardness in 36% of the samples, for boron in 16%, for ammonium, iron and manganese in 12%, for sodium and for chloride in 4% of samples. In 2017 a total of 33 samples were analyzed in Tulcea County; the following indicators have exceeded MAC trihalomethanes and iron in 3% of samples and manganese and fluorides in 9% of samples. For the analyzed indicators that exceeded the maximum admissible concentrations a database including the physical-chemical characteristics of drinking water at the exit from the treatment plants was created.

Drinking Water Quality and the Consumer

Water and Environment Journal, 1992

Public understanding of water quality is obtained primarily from the extensive media coverage of problems. This has contributed to a distrust of the water supply industry and of specific experts in this field. It is therefore important that the basis of standards for both microbiological and chemical parameters is absoulutely clear and scientifically defensible, since these are the yardsticks against which quality and safety will be judged. They are also the reference point from which political decisions on standards must be made. It is also important that the public is given some understanding of the comparative risks involved and that a proper balance is struck between maintaining microbiological quality and achieving chemical standards, particularly for disinfection by-products. Without this, the demand for more stringent standards in a search for absolute safety will result in more costly water, while standards approach the unachievable.

Effect of Regulations and Treatment Technologies on Water Distribution Infrastructure (PDF)

Changes in regulations on source water withdrawals, new treatment techniques, and maximum contaminant levels require drinking water utilities to continually change, upgrade, or replace their historic water sources and treatment practices. These change in treatment techniques invariably alter the water chemistry and can negatively affect the distribution system. This research, based on a partnership project between the Water Research Foundation and the National Research Council Canada, sought the consensus of experts from diverse areas of the drinking water industry in identifying current research needs to better understand potential water quality consequences for the distribution infrastructure. In addition, the authors developed a hierarchical relationship model that uses available research literature and expert knowledge to evaluate the effect of proposed changes on the distribution infrastructure.